Zur Elektronenstruktur metallorganischer Komplexe der f-Elemente: XXVII. Interpreation der optischen, magnetochemischen, ESR-und NMR-spektroskopischen Eigenschaften ausgewählter Neutralbasenaddukte, die sich vom Grundkörper Tris (n5-cyclopentadienyl)-neodym(III) ableiten

Abstract The absorption spectrum of (Cp- d 5 ) 3 Nd·THF- d 8 in hydrocarbon glasses and run as pellets was measured at room and low temperatures. The bands were assigned based on calculations assuming the crystal field parameters of the Nd complex were the same as for the previously analyzed Cp 3 Pr·MeTHF. The parameters of an empirical Hamiltonian wee fitted to the energies of 96 levels to give an r.m.s. deviation of 26 cm −1 . On the basis of the wave functions of the crystal field ground state obtained from these calculations, the observed EPR spectrum of Cp 3 Nd 0.06 La 0.94 ·THF could be explained. Making use of the calculated wave functions and eigenvalues the experimentally determined temperature dependence of μ 2 eff of powdered Cp 3 Nd·THF and of an oriented single crystal of Cp 3 Nd·Ncch 3 could be simulated. Assuming that the methyl protons of the γ-picoline ligand of Cp 3 Nd·γ-pic and (MeCp) 3 Nd· γ-pic, respectively, experience only an NMR shift of dipolar type, the paramagnetic anisotropy χ ∥ -χ ⊥ was estimated.